354 



USEFUL FIBER PLANTS OF THE WORLD. 



Table A. — For the examination of fibers, showing their behavior when treated with aqueous 

 solutions of the reagents specified. 



Caustic 



alkali as 



cau-1 ic 



Soda. 



Zinc chlorid. 



Entirely 



soluble. 



Partially 

 soluble. 



Completely sol- 

 able. 



Partially sol- 

 uble. 



Insoluble 



Partially sol- 

 able. 



Insoluble 



Insoluble. Insoluble 



Lei <1 acetat* 



Remarks. 



Alkali Mil ui ion 

 does not blacken. 



The soluble por- 

 tion d 68 U Ot 



blacken ; the in- 

 soluble does. 



Blackens 



A part blackens . . 



Does not blacken 



Silk. 



Mixed silk and 

 wool. 



Mixed silk, 

 > wool, and cot- 

 I ton. 



Wool 



The part insoluble in zinc chlorid 

 partly dissolves in caustic potash 

 the remainder is soluble : r. cu- 

 pramiuoniura. 

 On treatment with picric acid, pari io-n i 



colors yellow, part remains white. / Sllk and cotton. 

 On treatment with nitric acid, part (Mixed flax and 



turns yellow, part remains white, i cotton. 

 Chlorin. water, or ammonia colors the /New Zealand 

 fibers red brown, nitric acid ied. I Max. 

 Alcoholic t'uch- f 1 



sin (1-20) -ives I and H 2 S0 4 

 a permanent i give yellow, 

 color. 

 Potash soluble 'I and H 2 S0 4 i r1 



The fibers 

 rem a i n 

 colorless 

 on treat- 

 ment with 

 chlori n. 

 water, or 

 ammonia. 



.Hemp. 



dyes yellow. i gh e blue. 



Potash does not 

 color and t'uch \. 

 sin washes out. 



It will be seen that the first step is to treat with caustic alkali, 10 

 to 20 per cent, whereby animal fiber is dissolved, and vegetable fiber 

 not. If, now, lead acetate be added to the mixture it darkens imme- 

 diately from the formation of lead sulphid if wool is present. Or, if silk 

 be suspected, warm in strong sulphuric acid, when the silk will darken 

 rapidly and the wool more slowly. A solution of basic zinc chlorid. 

 may be made by taking a solution of J. 70 sp. gr. and dissolving therein 

 an excess of zinc oxid. In this fluid silk dissolves readily in the cold, 

 but wool and vegetable fibers remain unaffected. By heating a weighed 

 portion of the material in this bath for five minutes, then drying and 

 weighing, the amount of silk is determined by loss. On heating the 

 remainder in a 10 per cent solution of caustic soda, drying and weigh- 

 ing as before, the amount of wool is found ; the rest is vegetable fiber. 

 The more common vegetable fibers may be distinguished from each 

 other by means of the following table: 



Table B. — Showing the reactions of tin more important vegetable fibers 



Tiber. 



Iodin and zinc 

 chlorid. 



Iodin ami sul- 

 phuric acid. 



' luprammo- 



nium. 



Anilin sulphate. 



Phloroglucin 



Cotton 



Violet 



.. do 



do 



Brown yellow . . 



Dull violet 



Yellow tO \ iolet . 



Golden yellow- . . 

 fellow to brown 

 do 



Bine 



.... do 



do 



blue . . . 

 Dull blue . 



Blue solution. 

 do . 

















Hemp 



Jtlte 



do 



.... do 



do 



Tale yellow 



Golden yellow 



Violet red. 

 De< ]> red 









Fellow 





New Zealand 



flax. 

 Aloe 







Green ' 

 Yellow 



Bluish 



; 1 3 Up 



bluish. 



Y.llow iah 



do 



Bright yellow 



•i d 

 Pink. 

 Purpl 



